HBIO

Lab 1

Body Composition

Lab 2

Aerobic Capacity

Lab 3

Caloric Expenditure

Lab 4

Muscular Power

Fat mass categories

-essential fat

-storage fat

Fat free mass contains...

-protein (muscle)

-water

-minerals (bone)

Essential body fat of males

3%

Essential body fat of females

12%

8 indirect ways to measure body composition

1. Height/weight

2. BMI

3. Girth Measurement

4. Waist-to-hip ratio (WHR)

5. Skinfolds

6. Bioelectrical impedance

7. Hydrostatic weighing

8. BOD POD (Air Displacement)

2 ways to directly measure body composition

1. Chemical analysis

2. Cadaver analysis

Body Comp Gold Standard

hydrostatic weighing

Limits of hydrostatic weighing

-if subject does not let out all the air in their lungs the reading will be off

Limits of bioelectrical impedance

-based on body water

-hydration will effect the value given

BMI Equation

weight (kg)/height (m2)

FM Equation

total bodyweight x % fat

FFM Equation

total bodyweight - FM

Ideal Body Weight Equation (lbs)

FFM/1.0-ideal % fat (desired)

Female skinfold measurements

-triceps

-thigh

-suprailiac

Male skinfold measurements

-chest

-abdomen

-thigh

Apple shape (fat pattern)

-fat carried around the abdomen

-higher rates of obesity-related diseases

Pear shape (fat pattern)

-fat carried around the hips

-desirable shape

What does VO2 max stand for?

maximum amount of oxygen you body can use per minute

What does VO2 measure?

AEROBIC CAPACITY or your ability to perform sustained, moderate intensity exercise

Aerobic capacity (VO2) indicates the functional ability of

1. LUNGS to take in oxygen and transfer it to blood

2. CIRCULATORY SYSTEM (rbc's and hemoglobin) to bind & carry blood

3. HEART to pump blood

4. SKELETAL MUSCLE cells to extract oxygen from blood

VO2 max test (name)

open-circuit indirect calorimetry

Gold standard for measuring VO2 max

-open circuit indirect calorimetry

-max test (volunteers used)

Criteria for classifying VO2 test as maximal

Two must be met for the test to qualify:

1. A plateau in VO2

2. Peak RER > 1.0

3. Peak blood lactate level > 8.0 mM

4. Peak heart rate no less than 10 bpm below predicted max (least reliable)

Astrand-Rhyming Test Principles

-predictive

-requires only submaximal performance

-assumes heart rate-VO2 relationship at 50-90% max

-bike test (6 min)

Astrand-Rhyming Test Limitations (4)

1. Assumes linear relationship between HR and VO2

2. Assumes similar max HR for all subjects of same age

3. Assumes constant economy

4. Results based on heart rate response (heart rate can vary based on situations)

Anaerobic Energy Production

-ATP/CP and Glucose (Immediate energy and glycolysis)

-under 2 minutes of activity

-does not require oxygen

Aerobic Energy Production

-Krebs cycle (glucose and fat)

-energy produced slowly over longer period of time

-over 2 min

-requires oxygen

Gender differences in VO2 max

-men have higher average VO2 max

-men have more FFM

-men have higher hemoglobin values

Direct calorimetry

-measures heat given off in an air-tight chamber

-bomb calorimeter used for food

-human calorimeter used for humans

limits of direct calorimetry (3)

1. human calorimeter must be large and is impractical

2. exercising the chamber complicates the calculation because the machine (treadmill, bike) will produce heat

3. some heat is lost in perspiration and not measured

Indirect calorimetry

Can be used to indirectly measure the heat produced by a reaction by measuring VO2. (Remember, there is direct relationship between VO2 and heat produced). Data can then be used to calculate caloric expenditure

Part I of Caloric Expenditure Lab

-treadmill/heart rate test

-3 different intensities (after each plateau)

-creates a regression line to predict heart rate/VO2

Activities in Part II of Caloric Expenditure Lab

-walking

-jogging

-stair climbing

What does RER stand for?

Respiratory exchange ratio

RER equation

RER=VCO2/VO2

If RER is 0.82, thermal equivalent is...

-4.825 kcal/LVO2

Steady state RER

-60% from fat, 40% from carbs

-.82 RER value

-4.825 kcal/LVO2 thermal equivalent

RER 1.0

100% of energy coming from carbs

RER 0.7

100% of energy coming from fat

Limitations of indirect calorimetry

1. assumes linear heart rate/VO2 relationship only valid at (50-90% of max)

2. based on heart rate (can vary +/-5 based on different factors)

How many calories to lose 1 lb of fat

3,500 calories

Work (J) equation

work (J) = force (N) x distance (m)

Power equation (W)

power (W) = work (J) / time (sec)

Factors that determine the power output of a muscle

-ability to produce ATP

-muscular strength

-joint range of motion